Prior art monitoring and controlling systems for various applications, such as automated meter reading, prognostics, vending machines, and fire alarm and sprinkler systems utilize various communication protocols. Generally, these protocols utilize wireless RF communications either between transceivers or between a plurality of transceivers and a remote interrogator. The remote interrogator may then be coupled to a wide area network (WAN) which enables access to the transceivers by backend servers, workstations, etc.
In some instances, the RF transceivers may utilize a single-channel, substantially low-power communications protocol and, thus, have a limited range. The low-power applications are advantageous in certain remote applications, where a constant power supply is not available. For example, a transceiver coupled to a water meter cannot tap into any local power at the water meter, because typically there is no power. In this case, a battery is typically used. In order to maximize the life span of the battery, low-power transmissions are used. Low-power transmissions may also be advantageous because at certain frequency bands, a license from the Federal Communication Commission (FCC) is not required. The FCC requires certain devices to be licensed and/or comply with certain provisions if the devices radiate enough power within a given frequency spectrum over a given period.
Unfortunately, there are drawbacks to a low-power, single-channel communication protocol. In particular, the range of communication is directly proportional to the level of radiated power. Therefore, low power implies shorter communication range. Shorter communication range generally requires more infra-structure in a wireless system. Furthermore, single-channel communications (e.g., communications within one frequency channel, or on one carrier frequency) can be a problem if there is other electromagnetic radiation in a given area. Interference from other devices may cause noise at or near the specific single channel in which the RF transceivers are attempting to communicate, thus making communication unreliable, if not unfeasible.
Considering these drawbacks, it would be desirable to have a communication protocol that overcomes the disadvantages illustrated above. Furthermore, it would be advantageous for a systems provider for the communication devices (i.e., the RF transceivers and gateways) to be compatible with both communications protocols so that a communication upgrade would not require existing devices to be replaced. Instead the existing devices could be upgraded remotely through the system.